RdfNamedGraph class final

Represents an immutable named graph in an RDF dataset

A named graph is a pair consisting of:

• An IRI that uniquely identifies the graph within a dataset
• An RDF graph containing zero or more triples

This class provides a type-safe way to associate graph names with their content, enabling:

• Clear separation of concerns in multi-graph datasets
• Provenance and context tracking for RDF data
• Support for SPARQL GRAPH operations
• Dataset construction and manipulation

Design Principles

• Immutability: Once created, neither name nor graph can be changed
• Type Safety: Prevents mismatched name-graph associations
• Standard Compliance: Follows RDF 1.1 specification exactly
• Simplicity: Minimal interface focused on the essential pairing

Performance Characteristics

• Construction: O(1) - simple field assignment
• Access: O(1) - direct field access
• Memory: Minimal overhead beyond the constituent name and graph

Example:

// Create a named graph for organizational data
final orgGraph = RdfGraph(triples: organizationTriples);
final namedGraph = RdfNamedGraph(
  IriTerm('http://example.org/graphs/organization'),
  orgGraph
);

// Use in dataset operations
final dataset = RdfDataset.withGraphs([namedGraph]);
final retrievedGraph = dataset.graph(namedGraph.name);
assert(retrievedGraph == namedGraph.graph);